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How to embed a qwindow into qmainwindow



  • This is the main.cpp file for the basic shapes 3D example.

    int main(int argc, char **argv)
    {
        QApplication app(argc, argv);
        Window *view = new Window();
        QWidget *container = QWidget::createWindowContainer(view);
        QSize screenSize = view->screen()->size();
        container->setMinimumSize(QSize(200, 100));
        container->setMaximumSize(screenSize);
    
        QWidget *widget = new QWidget;
        QHBoxLayout *hLayout = new QHBoxLayout(widget);
        QVBoxLayout *vLayout = new QVBoxLayout();
        vLayout->setAlignment(Qt::AlignTop);
        hLayout->addWidget(container, 1);
        hLayout->addLayout(vLayout);
    
        widget->setWindowTitle(QStringLiteral("Basic shapes"));
    
        Qt3D::QAspectEngine engine;
        engine.registerAspect(new Qt3D::QRenderAspect());
        Qt3D::QInputAspect *input = new Qt3D::QInputAspect;
        engine.registerAspect(input);
        engine.initialize();
        QVariantMap data;
        data.insert(QStringLiteral("surface"), QVariant::fromValue(static_cast<QSurface *>(view)));
        data.insert(QStringLiteral("eventSource"), QVariant::fromValue(view));
        engine.setData(data);
    
        // Root entity
        Qt3D::QEntity *rootEntity = new Qt3D::QEntity();
    
        // Camera
        Qt3D::QCamera *cameraEntity = new Qt3D::QCamera(rootEntity);
        cameraEntity->setObjectName(QStringLiteral("cameraEntity"));
    
        cameraEntity->lens()->setPerspectiveProjection(45.0f, 16.0f/9.0f, 0.1f, 1000.0f);
        cameraEntity->setPosition(QVector3D(0, 0, -20.0f));
        cameraEntity->setUpVector(QVector3D(0, 1, 0));
        cameraEntity->setViewCenter(QVector3D(0, 0, 0));
        input->setCamera(cameraEntity);
    
        // FrameGraph
        Qt3D::QFrameGraph *frameGraph = new Qt3D::QFrameGraph();
        Qt3D::QForwardRenderer *forwardRenderer = new Qt3D::QForwardRenderer();
    
        forwardRenderer->setCamera(cameraEntity);
        forwardRenderer->setClearColor(QColor(QRgb(0x4d4d4f)));
        frameGraph->setActiveFrameGraph(forwardRenderer);
    
        // Setting the FrameGraph
        rootEntity->addComponent(frameGraph);
    
        // Scenemodifier
        SceneModifier *modifier = new SceneModifier(rootEntity);
    
        // Set root object of the scene
        engine.setRootEntity(rootEntity);
    
        // Create control widgets
        QCommandLinkButton *info = new QCommandLinkButton();
        info->setText(QStringLiteral("Qt3D ready-made meshes"));
        info->setDescription(QStringLiteral("Qt3D provides several ready-made meshes, like torus, cylinder, cube and sphere."));
        info->setIconSize(QSize(0,0));
    
        QCheckBox *torusCB = new QCheckBox(widget);
        torusCB->setChecked(true);
        torusCB->setText(QStringLiteral("Torus"));
    
        QCheckBox *cylinderCB = new QCheckBox(widget);
        cylinderCB->setChecked(true);
        cylinderCB->setText(QStringLiteral("Cylinder"));
    
        QCheckBox *cuboidCB = new QCheckBox(widget);
        cuboidCB->setChecked(true);
        cuboidCB->setText(QStringLiteral("Cuboid"));
    
        QCheckBox *sphereCB = new QCheckBox(widget);
        sphereCB->setChecked(true);
        sphereCB->setText(QStringLiteral("Sphere"));
    
        vLayout->addWidget(info);
        vLayout->addWidget(torusCB);
        vLayout->addWidget(cylinderCB);
        vLayout->addWidget(cuboidCB);
        vLayout->addWidget(sphereCB);
    
        QObject::connect(torusCB, &QCheckBox::stateChanged,
                         modifier, &SceneModifier::enableTorus);
        QObject::connect(cylinderCB, &QCheckBox::stateChanged,
                         modifier, &SceneModifier::enableCylinder);
        QObject::connect(cuboidCB, &QCheckBox::stateChanged,
                         modifier, &SceneModifier::enableCuboid);
        QObject::connect(sphereCB, &QCheckBox::stateChanged,
                         modifier, &SceneModifier::enableSphere);
    
        torusCB->setChecked(true);
        cylinderCB->setChecked(true);
        cuboidCB->setChecked(true);
        sphereCB->setChecked(true);
    
        // Show window
        widget->show();
        widget->resize(1200, 800);
    
        // Update the aspect ratio
        QSize widgetSize =  container->size();
        float aspectRatio = float(widgetSize.width()) / float(widgetSize.height());
        cameraEntity->lens()->setPerspectiveProjection(45.0f, aspectRatio, 0.1f, 1000.0f);
    
        return app.exec();
    }
    
    MainWindow.cpp
    

    What I want to do is create a ui where I create my own check boxes and embed the 3D rendering in an existing QWidget that I've placed in my mainwindow.ui (figure 1).

    Figure 1
    0_1547586174593_3bcff2ea-250f-4150-a47f-15f7306cb9de-image.png

    Here is the code that I used to do this:

    MainWindow::MainWindow(QWidget *parent) :
        QMainWindow(parent),
        ui(new Ui::MainWindow)
    {
        ui->setupUi(this);
        QWindow *view = new QWindow();
        QWidget *container = QWidget::createWindowContainer(view);
        container->setParent(ui->windowWidget);
        container->setMaximumSize(ui->windowWidget->size());
    
        Qt3D::QAspectEngine engine;
        engine.registerAspect(new Qt3D::QRenderAspect());
        Qt3D::QInputAspect *input = new Qt3D::QInputAspect;
        engine.registerAspect(input);
        engine.initialize();
        QVariantMap data;
        data.insert(QStringLiteral("surface"), QVariant::fromValue(static_cast<QSurface *>(view)));
        data.insert(QStringLiteral("eventSource"), QVariant::fromValue(view));
        engine.setData(data);
    
        // Root entity
        Qt3D::QEntity *rootEntity = new Qt3D::QEntity();
    
        // Camera
        Qt3D::QCamera *cameraEntity = new Qt3D::QCamera(rootEntity);
        cameraEntity->setObjectName(QStringLiteral("cameraEntity"));
    
        cameraEntity->lens()->setPerspectiveProjection(45.0f, 16.0f/9.0f, 0.1f, 1000.0f);
        cameraEntity->setPosition(QVector3D(0, 0, -20.0f));
        cameraEntity->setUpVector(QVector3D(0, 1, 0));
        cameraEntity->setViewCenter(QVector3D(0, 0, 0));
        input->setCamera(cameraEntity);
    
        // FrameGraph
        Qt3D::QFrameGraph *frameGraph = new Qt3D::QFrameGraph();
        Qt3D::QForwardRenderer *forwardRenderer = new Qt3D::QForwardRenderer();
    
        forwardRenderer->setCamera(cameraEntity);
        forwardRenderer->setClearColor(QColor(QRgb(0x4d4d4f)));
        frameGraph->setActiveFrameGraph(forwardRenderer);
    
        // Setting the FrameGraph
        rootEntity->addComponent(frameGraph);
    
        // Scenemodifier
        SceneModifier *modifier = new SceneModifier(rootEntity);
    
        QCheckBox *torusCB = ui->torusCB;
        QCheckBox *cylinderCB = ui->cylinderCB;
        QCheckBox *sphereCB = ui->sphereCB;
        QCheckBox *cuboidCB = ui->cuboidCB;
    
        torusCB->setChecked(true);
        cylinderCB->setChecked(true);
        cuboidCB->setChecked(true);
        sphereCB->setChecked(true);
    
        QObject::connect(torusCB, &QCheckBox::stateChanged,
                         modifier, &SceneModifier::enableTorus);
        QObject::connect(cylinderCB, &QCheckBox::stateChanged,
                         modifier, &SceneModifier::enableCylinder);
        QObject::connect(cuboidCB, &QCheckBox::stateChanged,
                         modifier, &SceneModifier::enableCuboid);
        QObject::connect(sphereCB, &QCheckBox::stateChanged,
                         modifier, &SceneModifier::enableSphere);
    
        // Set root object of the scene
        engine.setRootEntity(rootEntity);
    
    
        // Update the aspect ratio
        QSize widgetSize =  container->size();
        float aspectRatio = float(widgetSize.width()) / float(widgetSize.height());
        cameraEntity->lens()->setPerspectiveProjection(45.0f, aspectRatio, 0.1f, 1000.0f);
    }
    
    MainWindow::~MainWindow()
    {
        delete ui;
    }
    

    Here's my main function:

    int main(int argc, char *argv[])
    {
        QApplication a(argc, argv);
        MainWindow w;
        w.show();
    
        return a.exec();
    }
    
    

    What I end up with is this:

    0_1547586435409_f1c46cd9-e0b7-4b12-aadb-f3af0457f1bf-image.png

    I don't get the 3D rendering to show up. How would I go about fixing this? I thought that all I would need to do is change the parent of my window container to the Qwidget I have set up on my UI.


  • Lifetime Qt Champion

    Hi and welcome to devnet,

    What version of Qt are you using ?
    On what version of Ubuntu ?



  • I'm using Qt 5.10 on Ubuntu 14.04


  • Lifetime Qt Champion

    Can you test a more recent version of Qt ?
    Do you also get that if you use your distribution provided Qt ?


  • Moderators

    @nathanday89, does the unmodified Basic Shapes example work for you?



  • @JKSH Yes, the unmodified example works for me. I just want to embed the window that pops up inside a Qwidget in my mainwindow.ui instead of it opening a window of its own.


  • Lifetime Qt Champion

    What about running your code using your distribution provided Qt ?


  • Moderators

    @nathanday89 said in How to embed a qwindow into qmainwindow:

    Yes, the unmodified example works for me. I just want to embed the window that pops up inside a Qwidget in my mainwindow.ui instead of it opening a window of its own.

    Then you have just made a mistake while copying+pasting the code. Your original post contained Window *view = new Window(); -- this line does not exist in the Basic Shapes example.

    I recommend you make a copy of the original Basic Shapes project and gradually insert your own code into it.

    The first thing to try is replace the code that shows the top-level widget with your own QMainWindow:

    /* (Original code)
        
        // Show window
        widget->show();
        widget->resize(1200, 800);
    */
    
    // (Replacement code)
    QMainWindow myWindow;
    myWindow.setCentralWidget(widget);
    myWindow.show()
    

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